This invention relates to a removable recording medium on which data of plural categories, such as, for example, audio data and video data, are recorded, and a recording and reproducing apparatus for recording digital data on this recording medium.
In many recording and reproducing apparatuses, a removable recording medium is used. One advantage of such a removable recording medium is the ability to allow the digital data on the removable recording media to be processed directly by a computer. To further facilitate this advantage, the digital data is stored on the removable recording medium in a directory structure and file format that can be processed by a computer system. For example, a digital camera will store its still image digital data in a memory card, such as a flash RAM memory card, in a directory structure that a standard IBM PC compatible computer can access given the correct driver, and in a file format commonly used by a PC to store such image data, such as the JPEG file format.
Some recording and reproducing apparatus, which have hitherto been able to record and reproduce only data of one category, are now able to record and reproduce data of plural categories. Such categories include still image, audio, and video. This change in the art is a result of developments in the digital data processing field in recent years, and also of the development of increasing recording capacity of removable recording media. For example, formerly a digital camera could record only still image data. Now a new digital camera may be able to record moving picture or video data in addition to still image data, and may even have a microphone to record audio data.
In these recording and reproducing apparatus capable of recording and reproducing data of plural categories, a new problem arises. The different digital data categories, such as still image, audio, and video, will each have one or more particular file formats. Specific apparatuses may be able to mount the removable recording medium, but only access and process one category of data. For example, a new digital camera may record still image, audio, and video data on a removable recording medium. However, an audio player may only be able to process audio files, even though it is able to mount the particular removable recording medium. Thus, the plethora of data categories on the removable recording medium could render such an audio player unable to find or access the audio files. Moreover, a program on a personal computer will often only deal with a specific data category, or even a specific file format, and may have the same problem of accessing data on a removable recording medium with multiple data categories on it. In order to address this potential compatibility problem, a recording and reproducing apparatus capable of recording and reproducing data of plural categories is provided. It can record data of different categories in different directories on the removable recording medium. Each particular digital data category can have a corresponding directory. This allows apparatuses or programs the option to access a predetermined directory containing only one category of data. Subdirectories can be used to further categorise specific file formats under category directories.
This solution presents a new problem. If a recording and reproducing apparatus capable of recording and reproducing data of plural categories records data in different directories, it is not recording data in a list format which mirrors the chronological order in which the data was recorded. A problem presents itself if data on the removable recording medium needs to be accessed in chronological order rather than in categorical order, or if any time comparison must be done between data of different categories,
In view of the above-described status of the art, it is an object of the present invention to provide a recording and reproducing apparatus in which digital data of plural categories can be recorded onto a recording medium in categories but reproduced chronologically. Another object of the present invention is to provide a recording medium in which recorded digital data of plural categories can be reproduced chronologically.
One aspect of the present invention provides a recording and reproducing apparatus for recording and reproducing data of plural categories, and which records the data of plural categories in category-specific directories on a removable recording medium. The removable recording medium will therefore have a data structure in which data of different categories will be divided into category-specific directories. The recording and reproducing apparatus of this aspect of the present invention will include a micro-controller, or control micro-computer, and a working memory. The control microcomputer generates serial numbers for each particular file of digital data. The serial numbers are generated so that they will not be dependent on the category of the digital data, but on the chronological order of the digital data""s recording. The serial number is used by the micro-controller to generate a file name for each file of digital data. When the recording and reproducing apparatus reproduces the digital data on the removable recording media, it can then reproduce the digital data in its chronological order rather than categorical order by ordering the filenames by their serial numbers in the working memory.
A removable recording medium is another aspect of the present invention. The removable recording medium has digital data of plural categories recorded on it. The digital data of any given category is recorded in the directory corresponding to that category. The files of digital data are recorded by a filename including a serial number generated in the order of the data recorded without dependency upon the categories.